This invention relates to joystick controls for selectively altering electrical signals in accordance with the relative position of the joystick control and, more particularly, to a joystick control which generates digitally-coded signals.
This invention further relates to copending U.S. Patent Application Ser. No. 785,006 by Kastner et al, entitled System for Displaying Character and Graphic Information on a Color Video Display; Ser. No. 785,145, by Burson, entitled A Digital Joystick Control Interface System for Video Games and the Like; and Ser. No. 785,143 by Burson, entitled System to Control Velocity Vector of a Display Cursor, each filed of even date with and assigned to the Assignee of the present invention. This invention also relates to Ser. No. 791,913, by Trenkler et al, entitled Video Game with Portable Control Units, filed Apr. 28, 1977 and assigned to the Assignee of the present invention.
Prior art joystick controls, which alter electrical signals, have been of the analog type in which potentiometers are mounted in controlled relation to the joystick; one of the potentiometers being controlled with joystick movement in the X direction, and the other being controlled with joystick movement in the Y direction. The position of the joystick thereby determines the relative resistances of the two potentiometers which, in turn, alter electrical signals. If a digital signal is required to control a digital processor or the like, an analog-to-digital conversion circuit is required.
It is an object of the invention to provide an improved joystick control.
It is another object of the present invention to provide a digital joystick which directly generates digital-coded signals indicative of the X-Y position of the joystick.